Social impairment is a prominent feature of schizotypal personality disorder (SPD) and is often manifested in subjects by having few friends and long periods of unemployment. It is hypothesized that a combination of input and output emotional processing deficits explains the social and occupational failure of SPD subjects. In this R21 resubmission application simple sensory input and motor output of emotional faces and prosody will be compared in SPD and control subjects. The main hypothesis is that DSM-IV diagnosed SPD subjects, compared with control subjects, will exhibit deficits in information processing essential to social reciprocity (i.e., sensory processing of facial emotions and emotional prosody), and also deficits in the motoric output of signals related to social reciprocity (i.e., facial expressions and voice inflection), which are needed to convey social and emotional meaning. These four aspects of social reciprocity will be studied using behavioral measures, a computer-derived emotional expression task, videotapes, pitch analysis (measure of prosody), as well as by structural and functional MRI (fMRI). To achieve these aims, 24 neurolepticnaive SPD subjects age, gender, parental socio- economically matched to 24 comparison subjects, will be recruited from the community. A further rationale for studying SPD subjects is they are not psychotic and have not received neuroleptic medications. Yet SPD subjects share the same genetic diathesis as schizophrenia, and thus offer a unique opportunity to examine the behavior and the functional neuroanatomy of schizophrenia spectrum disorders, without multiple researches confounds such as medication effects and stress due to serious mental illness. Relevance to NIMH's mission: Understanding fundamental abnormalities in social reciprocity in SPD could have a significant impact on our conceptualization of these deficits in schizophrenia, which, in turn, might stimulate further social rehabilitation research.